A significant consequence of drug abuse is the cost of providing medical care for drug-related health complications. We propose to estimate these costs by investigating inpatient records from three statewide hospital discharge data base systems. Our primary objective is to model the economic impact of providing inpatient care for drug-related illnesses attributable to licit drugs taken without a prescription, illicit drugs, and alcohol. Our research has two overarching aims: a cost analysis of inpatient charges for patients with a drug-related primary diagnoses and a comparative analysis of patients with and without drug-related secondary diagnoses. The first portion of the research will calculate the average and total expenses for specific groups of illnesses to determine resources expended on drug-related health problems. The second portion will examine the impact of a drug-related comorbidity on hospital charges and payment sources. This research has several policy implications. For example, the findings could provide a base for future health care cost management, a health care component in treatment to preclude inpatient expenses, or aid in the evaluation of recently developed programs that link drug abuse services with primary medical care providers.